SU-GG-T-106: Simultaneous Integrated Boost Radiotherapy Using Volumetric Modulated Arc Therapy (RapidArc) in the Treatment of Head&Neck Cancer: A Dosi metric Comparison with Helical TomoTherapy and Intensity Modulated Radiotherapy

Purpose: To evaluate the treatment planning performance of volumetric modulated arc therapy (RapidArc) in patients with head and neck (HN the average minimum PTV70 doses were (97.9±1.0)%, (98.1±0.3)% and (96.7±1.9)%. The maximum and mean OAR doses for parotid glands, mandible and larynx were comparable while statistically significant differences were observed in the brainstem, spinal cord and esophagus. The average mean doses to brainstem, for instance, were 7±2.6 Gy (IMRT), 11.8±5.1 Gy (RA) and 20.2±6.3 Gy (HT). Conclusion:IMRT performed better in dose sparing for brainstem, spinal cord, and esophagus than did RapidArc and Tomotherapy when delivering SIB in patients with H&N cancer. Tomotherapy was found to provide the highest PTV dose homogeneity while the treatment delivery was more efficient with RA. Conflict of Interest: Research sponsored by Varian Medical Systems, Inc.